It's inIngenious as it is rugged and reliable, our V-Drive MOSFET power unit boosts the voltage to 17.2 volts so the amplifier can convert this into a 60Watts x 4. With power to spare for large musical peaks, this amplifier will deliver the full dynamic range of digital sources with stunning sound clarity from bass, mid and high ranges
gotta love it... I mean, my maths suggests 37 watts rms with a PERFECT amplifier.. which isn't going to happen.. 😛
and what about the heat?? I doubt it would be class D... maybe its not class AB either.. maybe its class G or H or whatever it was.. lol but you are NOT going to get 60 watts X 4 from 17.2 volts, in a small almost sealed metal box, inside a car.. 😛
gotta love it... I mean, my maths suggests 37 watts rms with a PERFECT amplifier.. which isn't going to happen.. 😛
and what about the heat?? I doubt it would be class D... maybe its not class AB either.. maybe its class G or H or whatever it was.. lol but you are NOT going to get 60 watts X 4 from 17.2 volts, in a small almost sealed metal box, inside a car.. 😛
SkinnyBoy said:
No doubt there is marketeering. However with a Bridge Tied Load (BTL) 150 watts is available to a 4 ohm load assuming you can go from rail to rail. They probably can't but at a power supply voltage of 17.2V...more power is available than you might imagine.
Heat is a good point though the dissipation of a BTL configuration is quite high. Check out the National appnote for the LM-3886 bridged configurations.
Scott
did I stuff up my maths?? hmm..... it is early morning...
no.. my maths is right.. 37 watts swinging the full 17.2 volt rail...
its a single 17.2 volts, not +- 17.2 volts...
no.. my maths is right.. 37 watts swinging the full 17.2 volt rail...
its a single 17.2 volts, not +- 17.2 volts...
Skinnyboy,
just like all headunits that say 4x40W or 4x50W and have 4x18W RMS, the alpine also doesn't give you 60W RMS. The installation guide of the Alpine CDA7894RB says the output power is 60W MAX, NOT RMS.
The RMS power is around 25W RMS.
Grtz, Joris
just like all headunits that say 4x40W or 4x50W and have 4x18W RMS, the alpine also doesn't give you 60W RMS. The installation guide of the Alpine CDA7894RB says the output power is 60W MAX, NOT RMS.
The RMS power is around 25W RMS.
Grtz, Joris
Vigier said:
but the guy at tonkins said the headunit would give more power than an old Clarion amp my friend bought and I fixed that it using +-20 volt rails...
and they had "50 watt" headunits, and then they released new models that were 60 watts...
and they DO NOT say max... or rms... or anything... 😛SkinnyBoy said:
Yup. You're right. I'm smoking illegal substances apparently. That's what I get for posting on 3 hours sleep.
Scott
Alpine might claim 25W RMS, but at what THD%?
Just save up and get an amp to drive your speakers.
Just save up and get an amp to drive your speakers.
so.. if an amp has a single 17.2 volt rail, is 37 watts the maximum power it can give, but with a huge amount of clipping?? or, would it be less than that cos the amp cannot swing the full rail even when it is clipping beyond belief??
Hi,
As far as I know, the 25W RMS is at 1% THD+N. (not measured by Alpine, but a German carhifi magazine)
If you don't want to turn the volume high, the power of those amplifiers is enough, but if you want a little more, you MUST have an external amplifier.
Right now I have a Pioneer DEH-P77MP (the CDA7894RB has been stolen a few months ago), and use a Emphaser EA4100-500 to get enough power. I NEVER use the amplifiers in the headunit because of the lack of power, en the poor quality (compared to good external amplifiers)
Grtz, Joris
As far as I know, the 25W RMS is at 1% THD+N. (not measured by Alpine, but a German carhifi magazine)
If you don't want to turn the volume high, the power of those amplifiers is enough, but if you want a little more, you MUST have an external amplifier.
Right now I have a Pioneer DEH-P77MP (the CDA7894RB has been stolen a few months ago), and use a Emphaser EA4100-500 to get enough power. I NEVER use the amplifiers in the headunit because of the lack of power, en the poor quality (compared to good external amplifiers)
Grtz, Joris
yeah.. I would imagine they could do 25 watts rms at a reasonable thd...
but they would NEVER do 50 watts, right?? not even with the amplifier clipping to its fullest, cos the voltage rail just isn't there... right??
but it could do near to like 35 watts with like 50% THD.. lol
but they would NEVER do 50 watts, right?? not even with the amplifier clipping to its fullest, cos the voltage rail just isn't there... right??
but it could do near to like 35 watts with like 50% THD.. lol
I'm just going to take my brothers advice and get a head unit which does not contain power amplifiers. That gives them more room to put in a better preamp etc. Makes perfect sense, however they're usually pretty costly. Too bad we can DIY mp3 CD players with really nice preamps (tubes even? Not that I use tubes).
Anyway, my head unit amplifier claims 160W max power into 4 channels. For one, I'm sure there's only two amplifiers in it, and I'm also sure it can't even hit 160W for even the smallest fraction of a second.
My next head unit will be ampless, and all my amps are likely to be gainclones.
Pete
Anyway, my head unit amplifier claims 160W max power into 4 channels. For one, I'm sure there's only two amplifiers in it, and I'm also sure it can't even hit 160W for even the smallest fraction of a second.
My next head unit will be ampless, and all my amps are likely to be gainclones.
Pete
so... we all agree that I can safely go into Tonkins and TELL them that these headunits won't do anywhere near 50watts rms even for a fraction of a second with 100% THD? lol
Yes, you can...
by the way, there is no reason to buy a headunit that hasn't got poweramplifiers in it. You can just buy a Alpine 7894RB of 9815 and don't connect the power-line for the poweramplifiers (there are separate connections for that!). The quality of the pre-amplifier is good enough.
Grtz, Joris
by the way, there is no reason to buy a headunit that hasn't got poweramplifiers in it. You can just buy a Alpine 7894RB of 9815 and don't connect the power-line for the poweramplifiers (there are separate connections for that!). The quality of the pre-amplifier is good enough.
Grtz, Joris
SkinnyBoy said:
1. Lies
2. damn lies
3. Statistics
4. Head unit power ratings
😛
ps;
5. Audio power rating in general 😉
SkinnyBoy said:
Check out Alpine's USA site for the 2004 year (www.alpine1.com). They have the CEA 2006 ratings for amps, and now they're a measly ~15W. BIG difference from 60W per channel.
cm961 said:
thats why I use my alpine 7939 with digital output.....just a preamp headunit and a better Dac than the reference 7909 unit
And that's why I went with the CDA-7995. It's nothing more than just a preamp, plus I would never run anything off of a HU amp anyway.
An externally hosted image should be here but it was not working when we last tested it.
yes.. well.. I am pretty sure that my friends speakers in his car sounded worse after a few days of use... 😛 lol ohh well.. and i really noticed the poor quality amp at any decent volume... he seemed to think it sounded good... it was clipping like mad... 😛
- Status
- Not open for further replies.